Protective hoods, such as those used by firefighters are exemplified in U.S. Pat. Nos. 4,972,520; 5,090,054; 5,873,132; 6,662,375 and 8,225,428, the disclosures of which are incorporated herein by reference, and are also available commercially from Honeywell International Inc. of Morristown, N.J. Protective hoods are also used by others such as race car drivers, rescue workers and other emergency personnel.
Protective hoods, as standalone items or when connected to a garment, as utilized in military, industrial, firefighting, recreational, or cold weather activities, (and other applications) have previously been constructed in two competing yet totally different types: hoods manufactured and constructed using woven textiles; and hoods manufactured and constructed of knit textiles. Each type has its own particular strengths and weaknesses wherein:
1. For both types of hoods the effectiveness and fit/function is impacted when utilized in combination with other head mounted gear such as one or more of the following (but not limited to): cold weather masks; partial face respirators; full face air masks; bump caps/helmets; prescription eyewear; protective glasses; protective goggles; night vision or infrared equipment; hearing protection muffs.
2. Due to the nature of knit textiles, hoods made from knit(s) have a greater ability to stretch and comfortably fit over the head, and/or the head with ancillary head worn gear, such as but not limited to respirators, air masks and eye/face protection. The down sides are that: the stretched knit material opens up the spaces between the yarns and allows a greater quantity and size of particulate matter, as well as air or liquid, to pass through as compared to the un-stretched knit material; eventually the rebound memory of the knit material deteriorates and the fit, both with and without ancillary head worn gear, becomes loose to the point of providing unsatisfactory performance; and a hood made of knit material provides a higher level of insulation value when the knit material is unstretched than does the same hood when the knit material is stretched, which is particularly an issue when the design is to provide protection from low or high temperature extremes.
3. Hoods made from woven textiles are more challenging when it comes to fitting to the head, both with and without ancillary head gear.
4. The inherent properties of insulation and particulate/air/liquid penetration of the woven textiles, coated/laminated and uncoated, for the most part remain nearly constant since the spaces between the yarns remain nearly the same size regardless of whether it is worn with or without ancillary head gear.